Hydrocarbon fuel blends



Patented Sept. 18, 1945 HYDROCARBON FUEL BLENDS Henry C. Paulsen, Elizabeth, N. 1., assignor to Standard Oil Development Company, a corporation of Delaware No Drawing. Application September a, 1941,

' Serial No. roam 8' Claims. (CI. 44-51) This invention deals with a method of treating fuels with a corrosion inhibiting additive to render the fuels non-corrosive to metals and, in general, to counteract objectionable efiects arising from unstable sulfur-containing compounds present in fuel compositions.

The corrosion inhibiting additive used in accordance with, the present invention is characterized by phenol sulfide type compounds which I have discovered to be surprisingly effective as corrosion inhibitors in petroleum fuel products whenincorporated therein in certain restricted amounts.

Hydrocarbon fuels of various types, including gasoline, heating oils, and Diesel fuels, are required to meet A. SKI. M. specifications on tolerance limits of corrosiveness, because it is desirable to avoid internal corrosion of pipes, storage tanks, refinery equipment, fuel supply containers, and engine or burner parts with which the fuels come into contact during handling and use. Generally, the metals contacted by the fuels are c nstructed of iron and copper, their alloys, and similar metals which are highly susceptible to corrosion believed to result mainly from the action of unstable or reactive'sulfur-containing compounds ordinarily present in mineral fuel oils, except when the fuels have been extremely well refined. I

It has also been found that water white petroleum distillates employed as fuels, even after very careful refining, may contain small amounts of unstable compounds of sulfur which tend to cause discoloration of the oil during storage, and more intensely when exposed to sunlight.

It has been found that in gasoline the corrosive sulfur-containing compounds are detrimental to the anti-knock quality of the fuel, particularly when the fuel is treated with lead alkyl antiknock agents. 'While in the case of Diesel fuels. although certain corrosive sulfur-containing compounds are beneficial to the ignition quality of the fuel in a compression-ignition engine, it is also desirable to reduce the corrosiveness of these fuels without impairing their ignition quality.

The effects of corrosiveness and instability are very undesirable and necessitate special and expensive processing methods to produce saleable fuel products, unless these effects can be suitably counteracted by an economical additive, such as those herein provided.

Thus, while it is the main object of this invention to reduce the corrosiveness of various types of fuels, it also embraces the use of a corrosion inhibiting additive which can be employed with benefit orwithout detriment to combustion qualities of various fuels.

The class of corrosion inhibiting additive found to accomplish the objects set forth in accordance with the present invention includes compounds which characteristically. contain the hydroxyaryl-sulfide group represented by the following formula:

wherein Ar is an aryl nucleus containing a hydroxy (0H) substituent, and S represents a sulfur substituent inthe aryl nucleus. In the preferred alkylated phenol sulfides for the present purposes, alkyl side chain substituentsare present in the aryl nuclei, including alkvl groups containing from about 3 to 6 carbon atoms, e. g., propyl, butyl, amyl, and hexyl radicals, and the substituted aryl nuclei are linked together through sulfur in a sulfide group.

' Representative examples of this class of compounds are the following:

'lertiary amyl phenol sulfide Tertiary amyl phenol disulflde Marw other compounds having the characteristic grouping of these compounds may be employed with modifications, such as the introduction of amin substituents or other groups into the aryl' lubricating oils in lows: A mol proportion of an alkylated phenol is dissolved in an inert diluent, such as ethylene dichloride (CHzClCH2Cl), and the solution is heated to boiling under reflux. Then a mol proportion of sulfur monochloride (SzClz) in the diluent is added slowly with stirring to the boiling solution of the alkylated phenol. The hydrogen chloride gas evolved during the reaction is withdrawn from the reaction zone through the reflux condenser. Whe the addition of the sulfur monochloride solution is completed, the boiling of the reaction mixture is continued for a period until no further effusion of hydrogen chloride occurs. The time of refluxing can be shortened by passing an inert gas, such as nitrogen, through the reaction mixture. The diluent and any unreacted material is removed from the reaction product loy distillation under vacuum at a temperature maintained preferably below about 150 C. I

By substitutingsulfur dichloride for the sul-, fur monochloride in the Process described, instead of the disulfide linkage, a monosuliide or thinether linkage is obtained. The organic reactant may be dicyclic, as in the case of naphthols, an unsaturated aliphatic compound may be made to react .with the phenol, and the phenol reactant may be modified, as indicated, e. g., to form alkoxyaryl sulfides.

Other configurations may result, depending upon the initial configuration of the allrylated phenol and eifects of the reaction used in preparing the sulfides.

While it is true that compounds of this type have been recommended to be useful anti-oxidants for lubricating oils when incorporated into amounts ranging from about 0.1% upwardly, it had never been foreseen that compounds of this nature containing sulfur constituents could be eflectively used as corrosion inhibitors in fuels. However, it is important to note that when the alkyl phenol sulfides are em- I ployed in accordance with the present invention as corrosion inhibitors, they must be used in Free sulfur and a number of inorganic and organic compounds containnig sulfur have been found to be powerful ignition promoters, but most of these substances tend to make the Diesel fuel TABLE 1 Eflects of inhibitors Ihbi ddd A.S.T.M. n i tore e per copper strip Fuel tested 100 ml. of fuel corrosion 1 hr.

at 212 F.

Gasoline None Fails.

Do 10 mg. ter-amyl phenol Passes.

sulfide. Do 10 mg. ter-amyl phenol Do.

disulfide. Air-blown heavy fuel.... None Fails.

Do 10 mg. ter-amyl phenol -Passcs. sulfide. Do 10 mg. ter-amyl phenol Do.

disulfid Colombian gas oil Passes. Colombian gas oil Fails.

0.1% N 34. I Colombian gas oil 10mg. ter-amyl phenol Passes.

0.1% N48 sulfide. Colombian gas oil 20 mg. ter-amyl phenol Do.

0.1% Nest. disulfide.

compounds themselves contain sulfur and have,

hitherto been regarded as corrosive materials.

It is further evident that the quantity of these f materials used to inhibit corrosion is illustrated in the following tables:

Tenn: 2

is critical, as

Eflect of tertiary amul phenol sulfide on gasoline (containing 8 mg. corrosivesullur/IOO ml.)

critically lower proportions than when they are used as eflectlve anti-oxidants in a lubricating oil, for otherwise they tend to actually increase the corrosiveness of the fuel. rosive inhibiting amounts fides are less than 0.05% by weight and preferably in the range of from about 0.03% to about 0.003% by weight of the fuel blend.

When the phenolic sulfide corrosion inhibitors of the alkyl phenol sulare employed to improve Diesel fuel compositions in reducing corrosiveness, they are beneficial in reducing corrosiveness-imparted to the fuel by sulfur-containnig ignition promoters without impairing the eifectlveness of these promoters.

1 Barely passes.

The foregoing data illustrates liow the inhibitor was found to be most effective in the proportion of about 10 mg. per ml. of the fuel and The effective cor-- how it loses the desired effectiveness as the proportion goes outside preferred limits in the range from about 0.003% to 0.03%. The same kinds of results-are evident when the disulfide inhibitor is used, except that the mono-sulfide is more eflectlvefand the efiectiveness of the inhibitors varies somewhat with the. type of fuel stock in which they are used.

It can also be noted that the. less drastic A. S. T. M. copper strip corrosion test at 122 F. shows up the effectiveness of these inhibitors tended tolbe illustrative as in the following the scope of to even a greater advantage, table:

TABLIB the invention. I Any modification or variation which conforms to the spirit of the Eject of tertiary m ny l. phenol disulflde as inhibimaintained I'with the addition of the inhibitor.

' "preparing the Diesel fuel compositions of reduced corrosiveness, any hydrocarbon oil suit- ]able fas a fuel basefor Diesel engines may be used. Ordinarily, the Diesel hydrocarbon fuel base employed has a boiling range above that of gasoline; and. more particularly, has a boiling range and viscosity corresponding to that of heavy -kerosene or gas oil dis'tillates which boil from about 375 F. to about 700 F. In some 1 instances, a'more narrowly cut fraction, such as one distillingflfrom' about 375 F. to 600 F., may I be used. The corrosive types of ignition promotencompounds are generally added to the Diesel fuel in small proportions of less than about 5% by 'weight. Extremely potent ignition promoters, such as nitrogen tetrasulfide (N454) and free sulfur are generally added in smaller quantitiesof about 0.1% to 0.5%.

The exact quantity of the phenol corrosion inhibitor used dependsupon the extent sulfide type in the fuel compositions to which it is desired that the corrosion be eliminated, the amounts and kinds of materials present in the fuel composition, the temperature and length of storage,

but many event, the proportion of this type of corrosion inhibitor should not be substantially outside the rangeof 0.001% to 0.05% by weight.

In utilizing the present invention for diminishing corrosivness of corrosive gasolines, the gasoline fuel stock to which the inhibitor is added my be a petroleum distillate, liquefied petroleum gases, or a synthetic fuel which has not been subjected to extensive refining so that the fuel contain's more than 4 mg. of reactive sulfur per 100 ml. and fails to passthe A. S. T. M. copper strip.

corrosion test. If the phenol sulfide inhibitor is jto beadded to a fuel which-satisfactorily passes thecorrosion test but which nevertheless contains some unstable or reactive sulfur, it is likewise to be employed in the same limited quantity to obtain a satisfactory non-corrosive product.

7 Other additives for enhancing the qualities of thefuels may be admixed,'such as oiliness agents;

dyes, and pour point depressors. Diesel fuels may contain viscosity modifiers, oxidation inhibitors, pour point depressants, and other ignition promotors. The gasoline type fuels may con.-v

tain anti-knock agents, dyes, gum fluxes, antioxidants,etc.

The foregoing description and examples are inonly and not as limitin rosive to metals blended ing essentially tor on corrosive Diesel fuel containing 'a cor-' rosive ignition promoter mesa" Inhibitor added Fueltested 1 N s +01% 4 1mg./100ml. 3mg.ll00 ml. 5mg.li00ml A. s. r. M. sh'igtestat z .1 our F Pass Passe Passes. 2honrs n (in do Do. zhour m do do Do. 4 hour I n B. P} do Do. 5 hour I n -Fails B. P.1 Do. I Ghouls rn do Fails 3.?) Barely. I v The addition of 0.1% by weight of N454 to the invention is intended to be included within the Colombian gas oil increased its cetane number scope of the claims. from 38 .to 41.3, which increase was satisfactorily I claim:

'soluble alkylated oxy-aryl sulfide in a range of by weight of said fuel stock.

about 0.001 to 0.05%

2. The method of rendering acorrosive sulfurcontaining fuel boiling between about about 700 F. non-corrosive to metals, which comprises adding to said fuel an oil-soluble alkyl phenol disulfide in an effective corrosion inhibiting amount of less than 0.05% fuel.

3. The method of rendering a corrosive sulfurcontaining fuel boiling between about 100 F. and about 700 F. non-corrosive to metals, which comprises adding to said fuel an alkyl phenol monosulfide in an effective corrosion inhibiting amount of 0.003% to 0.03% by weight of the fuel.

gasoline to Diesel fuel boiling rosive to metals containing an kylated oxy-aryl sulfide in an amount of 0.001% to 0.05% by weight of said product. i

5. A compression-ignition engine fuel consistof a hydrocarbon Diesel fuel oil containing reactive sulfur components which are normally corrosive to copper and blended with an oil-soluble sulfide of an alkylated phenol in a corrosion inhibiting amount between the approxirange normally cormate limits of .003 to .03%.

6. A Diesel fuel consisting essentiallyoi ahydrocarbon Diesel fuel base, from about 0.1% to about 5% of a sulfur-containing ignition promoter, and about 0.001% to 0.05% by weight of an alkylated phenol sulfide corrosion inhibitor.

'l. A motor fuel consisting essentially of gasoline hydrocarbons and normally corrosive to copper, blended with a sulfide of an alkylated phenol in a corrosion inhibiting amount of less than 0.05% by weight of the fuel. 1

8. A liquid hydrocarbon fuel product of the gasoline to Diesel fuel boiling range normally corwith from 3 to 20 milligrams of tertiary amyl'phenol mono-sulfide per 100 milliliters, said fuel being satisfactorily noncorrosive to copper for one hour at 212 F. under the A. S. T. M. copper strip corrosion test.

HENRY c. PAULSEN.

F. and

by weight of said 4. A liquid hydrocarbon fuel product of the oil-soluble all liquid hydrocarbon 

